Method for preparing nickel ferrite-based eutectic ceramic inert anode material

Abstract

A method of preparing a nickel ferrite-based eutectic ceramic inert anode material, in which a mixture powder of NiFe 2 O 4 -based spinel powder and nickel oxide-based powder is mixed with a binder, and granulated to obtain a granular material; the granular material is subjected to compression molding under 100-200 MPa to obtain a green body, which is pre-sintered to obtain a pre-sintered body; the pre-sintered body is melted in an inert gas atmosphere to obtain a molten material; the molten material is cooled at a rate of 1-100° C./min and solidified to obtain a ceramic solidified body; and the ceramic solidified body is processed at 1250-1400° C. for 2-6 h, and cooled to room temperature at a rate of 1-50° C./min to obtain the nickel ferrate-based eutectic ceramic inert anode material.

What is claimed is: 
     
         1 . A method of preparing a nickel ferrite-based eutectic ceramic inert anode material, comprising:
 (1) mixing a mixture powder of a NiFe 2 O 4 -based spinel powder and a nickel oxide-based powder with a binder, followed by granulation to obtain a granular material with a size of 10-30 mesh; subjecting the granular material to compression molding under 100-200 MPa to obtain a green body; and pre-sintering the green body at 1,100-1,300° C. for 2-5 h in a first inert gas atmosphere to obtain a pre-sintered body;   wherein the NiFe 2 O 4 -based spinel powder is 80-90% by weight of the mixture powder, and the nickel oxide-based powder is 10-20% by weight of the mixture powder; the binder is selected from the group consisting of polyvinyl alcohol, polyethylene glycol and a combination thereof; and the binder is 0.5-2% by weight of the mixture powder;   (2) melting the pre-sintered body in a second inert gas atmosphere to obtain a molten material; cooling and solidifying the molten material at a rate of 1-100° C./min, or casting the molten material followed by cooling and solidification at a rate of 1-100° C./min to obtain a ceramic solidified body; and   (3) processing the ceramic solidified body at 1250-1400° C. for 2-6 h, followed by cooling to room temperature at a rate of 1-50° C./min to obtain the nickel ferrate-based eutectic ceramic inert anode material.   
     
     
         2 . The method of  claim 1 , wherein the NiFe 2 O 4 -based spinel powder comprises 20-80 wt. % of NiFe 2 O 4 , 0-20 wt. % of ZnFe 2 O 4 , 0-20 wt. % of CuFe 2 O 4 , 0-20 wt. % of CoFe 2 O 4  and 0-20 wt. % of MnFe 2 O 4 , wherein an endpoint value 0% is excluded. 
     
     
         3 . The method of  claim 1 , wherein the nickel oxide-based powder comprises 20-80 wt. % of NiO, 0-20 wt. % of CaO, 0-20 wt. % of CeO 2 , 0-20 wt. % of ZrO 2 , 0-20 wt. % of Al 2 O 3 , and 0-20 wt. % of V 2 O 5 , wherein an endpoint value 0% is excluded. 
     
     
         4 . The method of  claim 1 , wherein the nickel oxide-based powder is pure NiO. 
     
     
         5 . The method of  claim 1 , wherein a particle size of the mixture powder of the NiFe 2 O 4 -based spinel powder and the nickel oxide-based powder is less than 100 mesh. 
     
     
         6 . The method of  claim 1 , wherein the mixture powder is prepared through steps of:
 subjecting the NiFe 2 O 4 -based spinel powder, the nickel oxide-based powder, a dispersant and water to ball milling for 12-24 h to obtain a ceramic slurry; and   drying the ceramic slurry followed by grinding to obtain the mixture powder;   wherein the dispersant is selected from the group consisting of ethanol, ethylene glycol, propylene glycol and a combination thereof, and the dispersant is 1-5% of a total weight of the NiFe 2 O 4 -based spinel powder and the nickel oxide-based powder; and   the water is 3-5 times the total weight of the NiFe 2 O 4 -based spinel powder and the nickel oxide-based powder.   
     
     
         7 . The method of  claim 1 , wherein in step (2), the pre-sintered body is melted in the second inert gas atmosphere at 1650-1850° C. for 1-2 h to obtain the molten material. 
     
     
         8 . The method of  claim 1 , wherein in step (2), the pre-sintered body is melted through arc melting, spark plasma melting, laser floating zone melting (LFZM), optical floating zone melting, selective electron beam melting, electromagnetic induction melting, Joule heating, or a combination thereof. 
     
     
         9 . The method of  claim 1 , wherein the nickel ferrate-based eutectic ceramic inert anode material has a relative density of 99-100%, a thermal shock resistance of 95-120%, a flexural strength of 70-110 MPa, a corrosion resistance of 5-50 μm, and an electrical conductivity of 8-30 S/cm.